The construction industry commonly uses single ply membranes to provide a waterproof barrier on flat or low-slope roofs. It is prohibitively expensive and difficult to produce and transport a single membrane that is sized to cover an entire roof surface. Thus, a plurality of individual membranes are provided and oriented in an overlapping arrangement. The overlapping portions, or splices, of these individual membranes must be secured together to ensure that the plurality of membranes form a single waterproof surface.
One attachment approach is to secure the adjoining membranes together using an adhesive. In certain embodiments, the adhesive is provided in the form of an adhesive tape. These tapes are positioned between adjacent membrane surfaces and when such surfaces are brought together, the membranes are thereafter secured together. In order to ensure that these tapes effectively bond the adjoining membranes, the areas where tape application occurs should be prepared using a primer. The primer application removes dirt and other debris that may inhibit bonding, as well the anti-sticking agent typically applied to the membrane prior to rolling. Further, the primer leaves a tacky or sticky surface upon which the adhesive tape is applied. This preparation process enhances the adhesion of the tape and consequently helps prevent leaking and/or separation.
Currently, primers are often applied to the membranes while in the field, just before the tape adhesive is applied to the membrane. The tape adhesive is packaged on release liners, which may be paper or plastic based material possessing engineered release characteristics to prevent unwanted adhesion and allow proper unrolling and placement of tape on the primed membrane. After the tape is applied to the primed membrane, the release liner is removed to expose the top side of the tape adhesive. The overlapping primed portion of the adjoining membrane is then mated to the tape adhesive to affix the two membranes together and create a watertight barrier at the lap areas between adjacent membrane panels.
Field priming of the membrane panels is performed by roofing mechanics. During application in the field, roof mechanics may be exposed to the primer chemicals and solvents by direct physical contact during the dispensing and application of the primer and indirectly to the primer's solvent fumes and volatile organic chemicals during the flash-off period.
Field priming of the membrane panels is also subject to improper application. For example, roof mechanics may not apply enough primer or apply it unevenly. They may apply tape before the flash-off period is complete, leading to a degradation of the resulting tape-adhesive bond. The mechanic may also apply the tape too long after primer application allowing dirt and moisture to collect on the primed surfaces. In each of the above instances, the integrity of the field seams may be jeopardized.
Pre-primed and pre-taped membranes have been previously contemplated. However, difficulties have arisen in the factory application of primers and adhesive tapes. One significant difficulty has arisen in developing efficient and effective methods of applying the primers and/or tapes to membranes in the factory. In order to prepare the membrane for installation on a roofing site it is necessary to pre-prime opposing edges of the membrane so that lap seams may be readily formed. The process for applying primer to both edges is time consuming, and if performed manually, labor intensive.
Therefore, there is a need for an improved method of pre-applying primer and/or adhesive tape to a membrane to improve the efficiency of the process.